The Danish National Space Centre [DNSC] did a study that proves the connection between early life on Earth and star formation in our Milky Way.
For the simple minded, scientists used some technique to see the relation between the amount of cosmic material coming from space from a period of intense supernovae explosions and star formation coincided with a period of intense growth and decline of bacteria. They then realised: This can’t be a coincidence. Cosmic material increases, bacteria growth-decline cycle increases. There has to be a connection. Atleast, that’s what I understood.
Centauri Dreams explains it more scientifically.
Read the abstract of original paper by Henrik Svensmark here.
Parallel Spirals 